U.S. patent application number 15/120199 was filed with the patent office on 2017-03-02 for vacuum base for container.
The applicant listed for this patent is Amcor Limited. Invention is credited to Peter A. BATES, Richard J. STEIH.
Application Number | 20170057724 15/120199 |
Document ID | / |
Family ID | 53878729 |
Filed Date | 2017-03-02 |
United States Patent
Application |
20170057724 |
Kind Code |
A1 |
BATES; Peter A. ; et
al. |
March 2, 2017 |
VACUUM BASE FOR CONTAINER
Abstract
A container including a finish, a shoulder portion, a sidewall,
and a base portion. The finish defines an opening. The shoulder
portion extends from the finish. The sidewall extends from the
shoulder portion and defines a volume of the container. The base
portion is at an end of the sidewall opposite to the shoulder
portion. The base portion includes a primary standing ring and a
secondary standing ring. The base portion is movable from an
as-blown position to an expanded position and from the expanded
position to a retracted position. In the as-blown and retracted
positions the primary standing ring is configured to support the
container upright. In the expanded position the secondary standing
ring is configured to support the container upright.
Inventors: |
BATES; Peter A.; (Sylvania,
OH) ; STEIH; Richard J.; (Jackson, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Amcor Limited |
Hawthorn, Victoria |
|
AU |
|
|
Family ID: |
53878729 |
Appl. No.: |
15/120199 |
Filed: |
February 20, 2014 |
PCT Filed: |
February 20, 2014 |
PCT NO: |
PCT/US2014/017424 |
371 Date: |
August 19, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65D 21/0231 20130101;
B65D 51/245 20130101; B65D 1/0246 20130101; B65D 79/005 20130101;
B65D 1/0276 20130101 |
International
Class: |
B65D 79/00 20060101
B65D079/00; B65D 21/02 20060101 B65D021/02; B65D 51/24 20060101
B65D051/24; B65D 1/02 20060101 B65D001/02 |
Claims
1. A container comprising: a finish defining an opening; a shoulder
portion extending from the finish; a sidewall extending from the
shoulder portion and defining a volume of the container; and a base
portion at an end of the sidewall opposite to the shoulder portion
and including a primary standing ring and a secondary standing
ring, the base portion movable from an as-blown position to an
expanded position and from the expanded position to a retracted
position; wherein: in the as-blown and retracted positions the
primary standing ring is configured to support the container
upright; and in the expanded position the secondary standing ring
is configured to support the container upright.
2. The container of claim 1, wherein in the as-blown position the
secondary standing ring is recessed within the container.
3. The container of claim 1, wherein in the expanded position, the
secondary standing ring protrudes outward beyond the primary
standing ring and a base end of the container.
4. The container of claim 2, wherein in the retracted position the
secondary standing ring is closer to the finish than the primary
standing ring is.
5. The container of claim 2, wherein the secondary standing ring is
in substantially the same position in both the retracted position
and the as-blown position.
6. The container of claim 2, wherein the secondary standing ring is
one of closer to or further from the finish in the retracted
position than when in the as-blown position.
7. The container of claim 1, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 18% to
about 28% of a total planar area of the base portion.
8. The container of claim 1, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 23% of a
total planar area of the base portion.
9. The container of claim 1, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 2
degrees with respect to a longitudinal axis of the container.
10. The container of claim 1, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 0.5
degrees with respect to a longitudinal axis of the container.
11. The container of claim 1, wherein the secondary standing ring
is between the primary standing ring and a central zone of the base
portion.
12. The container of claim 11, wherein a longitudinal axis of the
container extends through the central zone, the central zone
configured to move along the longitudinal axis as the base portion
moves from the as-blown position to the expanded position, and from
the expanded position to the retracted position.
13. The container of claim 12, wherein the central zone is
configured to not flex as the base portion moves from the as-blown
position to the expanded position, and from the expanded position
to the retracted position.
14. The container of claim 12, wherein the secondary standing ring
is configured to flex as the base portion moves from the as-blown
position to the expanded position, and from the expanded position
to the retracted position.
15. The container of claim 12, wherein the container is a hot fill
container; wherein the base portion is configured to move from the
as-blown position to the expanded position when the container is
subject to increased temperature and increased pressure during hot
fill; and wherein the base portion is configured to move from the
expanded position to the retracted position as the hot fill
contents cool and internal vacuum pressure increases.
16. The container of claim 1, wherein the sidewall is without a
vacuum panel.
17. The container of claim 1, wherein the base portion defines a
receptacle configured to receive therein a closure of a similar
container to facilitate container stacking.
18. The container of claim 1, wherein a closure of the container
includes a vacuum indicator.
19. A container comprising: a finish defining an opening; a
shoulder portion extending from the finish; a sidewall extending
from the shoulder portion and defining a volume of the container;
and a base portion at an end of the sidewall opposite to the
shoulder portion, the base portion movable from an as-blown
position to an expanded position, and from the expanded position to
a retracted position, the base portion including: a primary
standing ring, a central zone, and a secondary standing ring
between the primary standing ring and the central zone; wherein:
the central zone is configured to move along a longitudinal axis of
the container without flexing as the base portion moves from the
as-blown position to the expanded position, and from the expanded
position to the retracted position; in the as-blown and the
retracted positions the primary standing ring is configured to
support the container upright; and in the expanded position the
secondary standing ring extends out from within the container and
beyond the primary standing ring in order to support the container
upright.
20. The container of claim 19, wherein the central zone includes a
side surface that remains equidistant from the longitudinal axis as
the central zone moves along the longitudinal axis.
21. The container of claim 19, wherein in the retracted position
the secondary standing ring is recessed further within the
container than when in the as-blown position.
22. The container of claim 19, wherein the sidewall is without a
vacuum panel.
23. The container of claim 19, wherein the container is a hot fill
container; wherein the base portion is configured to move from the
as-blown position to the expanded position when the container is
subject to increased temperature and increased pressure during hot
fill; and wherein the base portion is configured to move from the
expanded position to the retracted position as the hot fill
contents cool and internal vacuum pressure increases.
24. The container of claim 19, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 18% to
about 28% of a total planar area of the base portion.
25. The container of claim 19, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 23% of a
total planar area of the base portion.
26. The container of claim 19, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 2
degrees with respect to the longitudinal axis of the container.
27. The container of claim 19, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 0.5
degrees with respect to the longitudinal axis of the container.
28. A container comprising: a finish defining an opening; a
shoulder portion extending from the finish; a sidewall extending
from the shoulder portion and defining a volume of the container;
and a base portion at an end of the sidewall opposite to the
shoulder portion, the base portion movable from an as-blown
position to an expanded position, and from the expanded position to
a retracted position, the base portion including: a primary
standing ring, a central zone, and a secondary standing ring
between the primary standing ring and the central zone; a closure
configured to couple with the finish to seal the container closed,
the closure including a vacuum seal indicator; wherein: the central
zone is configured to move along a longitudinal axis of the
container as the base portion moves from the as-blown position to
the expanded position, and from the expanded position to the
retracted position; in the as-blown and the retracted positions the
primary standing ring is configured to support the container
upright; and in the expanded position the secondary standing ring
extends out from within the container and beyond the primary
standing ring in order to support the container upright.
29. The container of claim 28, wherein the central zone is
configured to move along the longitudinal axis of the container
without flexing.
30. The container of claim 28, wherein the sidewall is entirely
smooth and without a vacuum panel.
31. The container of claim 28, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 18% to
about 28% of a total planar area of the base portion.
32. The container of claim 28, wherein the base portion includes a
central zone through which a longitudinal axis of the container
extends, the central zone has a planar area that is about 23% of a
total planar area of the base portion.
33. The container of claim 28, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 2
degrees with respect to the longitudinal axis of the container.
34. The container of claim 28, wherein as the container transitions
from the as-blown position to the expanded position and to the
retracted position, the base portion tilts less than about 0.5
degrees with respect to the longitudinal axis of the container.
Description
[0001] FIELD
[0002] The present disclosure relates to a vacuum base for a
container.
BACKGROUND
[0003] This section provides background information related to the
present disclosure, which is not necessarily prior art.
[0004] As a result of environmental and other concerns, plastic
containers, more specifically polyester and even more specifically
polyethylene terephthalate (PET) containers, are now being used
more than ever to package numerous commodities previously packaged
in glass containers. Manufacturers and fillers, as well as
consumers, have recognized that PET containers are lightweight,
inexpensive, recyclable and manufacturable in large quantities.
[0005] Manufacturers currently supply PET containers for various
liquid commodities, such as juice and isotonic beverages. Suppliers
often fill these liquid products into the containers while the
liquid product is at an elevated temperature, typically between
68.degree. C.-96.degree. C. (155.degree. F.-205.degree. F.) and
usually at approximately 85.degree. C. (185.degree. F.). When
packaged in this manner, the hot temperature of the liquid
commodity sterilizes the container at the time of filling. The
bottling industry refers to this process as hot filling, and
containers designed to withstand the process as hot-fill or
heat-set containers.
[0006] The hot filling process is acceptable for commodities having
a high acid content, but not generally acceptable for non-high acid
content commodities. Nonetheless, manufacturers and fillers of
non-high acid content commodities desire to supply their
commodities in PET containers as well. For non-high acid
commodities, pasteurization and retort are the preferred
sterilization processes. Pasteurization and retort both present a
challenge for manufactures of PET containers in that heat-set
containers cannot withstand the temperature and time demands
required of pasteurization and retort.
[0007] Pasteurization and retort are both processes for cooking or
sterilizing the contents of a container after filling. Both
processes include the heating of the contents of the container to a
specified temperature, usually above approximately 70.degree. C.
(approximately 155.degree. F.), for a specified length of time
(20-60 minutes). Retort differs from pasteurization in that retort
uses higher temperatures to sterilize the container and cook its
contents. Retort also applies elevated air pressure externally to
the container to counteract pressure inside the container. The
pressure applied externally to the container is necessary because a
hot water bath is often used and the overpressure keeps the water,
as well as the liquid in the contents of the container, in liquid
form, above their respective boiling point temperatures.
[0008] PET is a crystallizable polymer, meaning that it is
available in an amorphous form or a semi-crystalline form. The
ability of a PET container to maintain its material integrity
relates to the percentage of the PET container in crystalline form,
also known as the "crystallinity" of the PET container. The
following equation defines the percentage of crystallinity as a
volume fraction:
% Crystallinity = .rho. - .rho. .alpha. .rho. c - .rho. .alpha.
.times. 100 ##EQU00001##
where .rho. is the density of the PET material; .rho..sub..alpha.
is the density of pure amorphous PET material (1.333 g/cc); and
.rho..sub.c is the density of pure crystalline material (1.455
g/cc).
[0009] Container manufactures use mechanical processing and thermal
processing to increase the PET polymer crystallinity of a
container. Mechanical processing involves orienting the amorphous
material to achieve strain hardening. This processing commonly
involves stretching a PET preform along a longitudinal axis and
expanding the PET preform along a transverse or radial axis to form
a PET container. The combination promotes what manufacturers define
as biaxial orientation of the molecular structure in the container.
Manufacturers of PET containers currently use mechanical processing
to produce PET containers having approximately 20% crystallinity in
the container's sidewall.
[0010] Thermal processing involves heating the material (either
amorphous or semi-crystalline) to promote crystal growth. On
amorphous material, thermal processing of PET material results in a
spherulitic morphology that interferes with the transmission of
light. In other words, the resulting crystalline material is
opaque, and thus, generally undesirable. Used after mechanical
processing, however, thermal processing results in higher
crystallinity and excellent clarity for those portions of the
container having biaxial molecular orientation. The thermal
processing of an oriented PET container, which is known as heat
setting, typically includes blow molding a PET preform against a
mold heated to a temperature of approximately 120.degree.
C.-130.degree. C. (approximately 248.degree. F.-266.degree. F.),
and holding the blown container against the heated mold for
approximately three (3) seconds. Manufacturers of PET juice
bottles, which must be hot-filled at approximately 85.degree. C.
(185.degree. F.), currently use heat setting to produce PET bottles
having an overall crystallinity in the range of approximately
25%-35%.
[0011] After being hot-filled, the heat-set containers are capped
and allowed to reside at generally the filling temperature for
approximately five (5) minutes at which point the container, along
with the product, is then actively cooled prior to transferring to
labeling, packaging, and shipping operations. The cooling reduces
the volume of the liquid in the container. This product shrinkage
phenomenon results in the creation of a vacuum within the
container. Generally, vacuum pressures within the container range
from 1-300 mm Hg less than atmospheric pressure (i.e., 759 mm
Hg-460 mm Hg). If not controlled or otherwise accommodated, these
vacuum pressures result in deformation of the container, which
leads to either an aesthetically unacceptable container or one that
is unstable.
[0012] In many instances, container weight is correlated to the
amount of the final vacuum present in the container after this
fill, cap and cool down procedure, that is, the container is made
relatively heavy to accommodate vacuum related forces. Similarly,
reducing container weight, i.e., "lightweighting" the container,
while providing a significant cost savings from a material
standpoint, requires a reduction in the amount of the final vacuum.
Typically, the amount of the final vacuum can be reduced through
various processing options such as the use of nitrogen dosing
technology, minimize headspace or reduce fill temperature. One
drawback with the use of nitrogen dosing technology however is that
the maximum line speeds achievable with the current technology is
limited to roughly 200 containers per minute. Such slower line
speeds are seldom acceptable. Additionally, the dosing consistency
is not yet at a technological level to achieve efficient
operations. Minimizing headspace requires more precession during
filling, again resulting in slower line speeds. Reducing fill
temperature is equally disadvantageous as it limits the type of
commodity suitable for the container.
[0013] Typically, container manufacturers accommodate vacuum
pressures by incorporating structures in the container sidewall.
Container manufacturers commonly refer to these structures as
vacuum panels. Traditionally, these paneled areas have been
semi-rigid by design, unable to accommodate the high levels of
vacuum pressures currently generated, particularly in lightweight
containers. In some applications, these paneled areas may not be
aesthetically pleasing.
[0014] Development of technology options to achieve an ideal
balance of light-weighting and design flexibility are of particular
interest. According to the principles of the present teachings, an
alternative vacuum absorbing capability is provided within the
container base. Traditional hot-fill containers accommodate nearly
all vacuum forces within the body (or sidewall) of the container
through deflection of the vacuum panels. These containers are
typically provided with a rigid base structure that substantially
prevents deflection thereof and thus tends to be heavier than the
rest of the container. In contrast, Applicants utilize a
lightweight base designed to accommodate nearly all vacuum
forces.
[0015] Therefore, an object of the present teachings is to achieve
the optimal balance of weight and vacuum performance of both the
container body and base. To achieve this, in some embodiments, a
hot-fill container is provided that comprises a lightweight,
flexible base design that is easily moveable to accommodate vacuum,
but does not require a dramatic inversion or snap-through, thus
eliminating the need for a heavy sidewall or vacuum panels.
Utilizing a lightweight base design to absorb vacuum forces enables
an overall light-weighting, design flexibility, and permits use of
a smooth, "glass-like," aesthetically pleasing sidewall, which need
not include vacuum panels.
SUMMARY
[0016] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0017] The present teachings provide for a container including a
finish, a shoulder portion, a sidewall, and a base portion. The
finish defines an opening. The shoulder portion extends from the
finish. The sidewall extends from the shoulder portion and defines
a volume of the container. The base portion is at an end of the
sidewall opposite to the shoulder portion. The base portion
includes a primary standing ring and a secondary standing ring. The
base portion is movable from an as-blown position to an expanded
position and from the expanded position to a retracted position. In
the as-blown and retracted positions the primary standing ring is
configured to support the container upright. In the expanded
position the secondary standing ring is configured to support the
container upright.
[0018] The present teachings further provide for a container
including a finish, a shoulder portion, a sidewall, and a base
portion. The finish defines an opening. The shoulder portion
extends from the finish. The sidewall extends from the shoulder
portion and defines a volume of the container. The base portion is
at an end of the sidewall opposite to the shoulder portion. The
base portion is movable from an as-blown position to an expanded
position, and from the expanded position to a retracted position.
The base portion includes: a primary standing ring, a central zone,
and a secondary standing ring between the primary standing ring and
the central zone. The central zone is configured to move along a
longitudinal axis of the container without flexing as the base
portion moves from the as-blown position to the expanded position,
and from the expanded position to the retracted position. In the
as-blown and the retracted positions the primary standing ring is
configured to support the container upright. In the expanded
position the secondary standing ring extends out from within the
container and beyond the primary standing ring in order to support
the container upright.
[0019] The present teachings also provide for a container including
a finish, a shoulder portion, a sidewall, a base portion, and a
closure. The finish defines an opening. The shoulder portion
extends from the finish. The sidewall extends from the shoulder
portion and defines a volume of the container. The base portion is
at an end of the sidewall opposite to the shoulder portion. The
base portion is movable from an as-blown position to an expanded
position, and from the expanded position to a retracted position.
The base portion includes a primary standing ring, a central zone,
and a secondary standing ring between the primary standing ring and
the central zone. The closure is configured to couple with the
finish to seal the container closed. The closure may include a
vacuum seal indicator. The central zone is configured to move along
a longitudinal axis of the container as the base portion moves from
the as-blown position to the expanded position, and from the
expanded position to the retracted position. In the as-blown and
the retracted positions the primary standing ring is configured to
support the container upright. In the expanded position the
secondary standing ring extends out from within the container and
beyond the primary standing ring in order to support the container
upright.
[0020] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0021] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0022] FIG. 1 is a side view of a container according to the
present teachings;
[0023] FIG. 2 is a perspective view of a base portion of the
container of FIG. 1;
[0024] FIG. 3 is a bottom view of the base portion of the container
of FIG. 1;
[0025] FIG. 4 is a cross-sectional view taken along line 4-4 of
FIG. 3;
[0026] FIG. 5 illustrates movement of the base portion of the
container of FIG. 1 from an as-blown position to an extended
position;
[0027] FIG. 6 illustrates the base portion of the container of FIG.
1 in the as-blown position C, in a retracted position the base
portion is at E1, E2, or at any point therebetween;
[0028] FIG. 7 is a perspective view illustrating the container of
FIG. 1 with another container stacked thereon, the container of
FIG. 1 has a modified finish and includes a closure;
[0029] FIG. 8 is a cross-sectional view taken along line 8-8 of
FIG. 7;
[0030] FIG. 9 is a graph illustrating displacement of the base
portion of the container of FIG. 1 versus vacuum pressure; and
[0031] FIG. 10 is a graph illustrating displacement of the base
portion of a prior art container versus vacuum pressure.
[0032] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0033] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0034] With initial reference to FIG. 1, a container according to
the present teachings is generally illustrated at reference numeral
10. The container 10 generally includes a body portion 12, a
shoulder portion 14, a finish 16, and a base portion 18
[0035] The body portion 12 includes a sidewall 22, which is
cylindrical or generally cylindrical, and defines a volume 24 of
the container 10. The sidewall 22 is generally smooth and without
vacuum panels, which advantageously provides the container 10 with
a "glass-like" appearance. Between the body portion 12 and the base
portion 18 is a first recessed ring 26. Between the body portion 12
and the shoulder portion 14 is a second recessed ring 28.
[0036] The shoulder portion 14 extends from the second recessed
ring 28 towards the finish 16. The shoulder portion 14 includes an
outer diameter portion 30, and a tapered surface 32. The tapered
surface 32 extends from the outer diameter portion 30 towards the
finish 16, and is tapered such that the tapered surface 32 has a
progressively smaller diameter as it extends away from the outer
diameter portion 30. The tapered surface 32 extends from the outer
diameter portion to neck 34.
[0037] The finish 16 extends from the neck 34 and includes a first
annular rib 36 and a second annular rib 38. The first annular rib
36 is between the second annular rib 38 and the neck 34. Each of
the first annular rib 36 and the second annular rib 38 extend
outward beyond an annular sidewall 40 of the finish 16.
[0038] Extending outward from the annular sidewall 40 are threads
42. The threads 42 are configured to cooperate with any suitable
closure in order to close the container 10 by covering an opening
defined by the finish 16, which leads to the volume 24. The annular
sidewall 40 extends to an upper end 44 of the container 10 at which
the opening is defined. The upper end 44 is opposite to a base end
46 of the container 10 at the base portion 18. The finish 16 can be
any suitable finish, such as a wide-mouth blow trim finish of any
suitable size, such as about 43 mm or greater, or an injected
finish of about 43 mm or smaller, for example.
[0039] The container 10 can be any suitable container, such as a
blow-molded, biaxially oriented container with a unitary
construction made from a single- or multi-layer material. An
exemplary stretch-molding, heat-setting process for making the
container 10 generally includes manufacture of a preform (not
illustrated) of a suitable polyester material, such as a
polyethylene terephalate (PET), having a shape known to those
skilled in the art as being similar to a test-tube with a generally
cylindrical cross-section and a length typically about fifty
percent (50%) that of a height of the container 10.
[0040] A machine (not illustrated) places the preform heated to a
temperature between approximately 190.degree. F. to 250.degree. F.
(approximately 88.degree. C. to 121.degree. C.) into a mold cavity
having a shape similar to that of the container 10. The mold cavity
is heated to a temperature between approximately 250.degree. F. to
350.degree. F. (approximately 121.degree. C. to 177.degree. C.). A
stretch rod apparatus (not illustrated) stretches or extends the
heated preform within the mold cavity to a length approximately
that of the container 10 thereby molecularly orienting the
polyester material in an axial direction generally corresponding
with the longitudinal axis A of the container 10. When the stretch
rod extends the preform, air with a pressure between 300 PSI to 600
PSI (2.07 MPa to 4.14 MPa) assists in extending the preform in the
axial direction and expanding the preform in a circumferential or
hoop direction thereby substantially conforming the polyester
material to the shape of the mold cavity and further molecularly
orienting the polyester material in a direction generally
perpendicular to the axial direction, thus establishing the biaxial
molecular orientation of the polyester material in most of the
container.
[0041] Typically, material with the finish 16 and a sub-portion of
the base portion 18 are not substantially molecularly oriented. The
pressurized air holds the mostly biaxial molecularly oriented
polyester material against the mold cavity for a period of
approximately two to five seconds before removal of the container
from the mold cavity. To achieve appropriate material distribution
within the base portion 18, an additional stretch-molding step
substantially as taught by U.S. Pat. No. 6,277,321, which is
incorporated herein by reference, may be used. Alternatively, other
manufacturing methods using other conventional thermoplastic
materials including, for example, high density polyethylene,
polypropylene, polyethylene naphthalate (PEN), a PET/PEN blend or
copolymer, and various multi-layer structures may be used to
manufacture the container 10.
[0042] For hot-fill bottling applications, bottlers generally fill
the container 10 with a liquid or product at an elevated
temperature between approximately 195.degree. F. to 205.degree. F.
(approximately 90.5.degree. C. to 96.degree. C.) and seal the
container 10 with a closure before cooling. As the sealed container
10 cools, a vacuum, or negative pressure, forms inside causing the
container 10 to change shape, particularly the base portion 18 as
described herein. In addition, the container 10 may be suitable for
other high-temperature pasteurization or retort filling processes,
or other thermal processes as well.
[0043] With continued reference to FIG. 1, and additional reference
to FIGS. 2-5, the base portion 18 will now be described in detail,
as well as movement of the base portion 18 in response to
temperatures and pressures experienced by the container 10 during
hot-filling of the container 10. FIGS. 1-4 illustrate the base
portion 18 in an "as-blown" configuration approximately 72 hours
after having been formed, and having been stored at normal
conditions. FIG. 5 illustrates the as-blown orientation of the base
portion 18 at C. FIG. 5 also illustrates the base portion 18 in an
extended position and orientation at D, which is described in
further detail herein.
[0044] The base portion 18 generally includes a primary standing
ring 110 at an outer diameter thereof. At an axial center 112 of
the base portion 18 is a gate area 114, which is generally
circular. The longitudinal axis A of the container 10 extends
through the axial center 112. Extending from the axial center 112
and the gate area 114 is a center surface 116. From the gate area
114, the center surface 116 can extend inward in the direction of
the body portion 12 and thus away from the base end 46, as
illustrated in FIG. 5.
[0045] A side surface 118 extends from the center surface 116
towards the base end 46. The side surface 118 is angled such that
it slopes away from the longitudinal axis A as the side surface 118
extends in the direction of the base end 46. As illustrated in
FIGS. 2-4, the side surface 118 includes ribbed portions 120, which
are recessed within the side surface 118.
[0046] The side surface 118 extends from the center surface 116 to
generally an inwardly extending portion 122. With respect to an
outer side of the base portion 18, the inwardly extending portion
122 is generally concave. The center surface 116, the side surface
118, and the inwardly extending portion 122 (or at least a portion
of the inwardly extending portion 122) generally define a central
zone B of the base portion 18, as illustrated in FIGS. 4 and 5. The
central zone B has a planar area that is about 18% to about 28% of
a total planar area of the base portion 18 as measured across the
standing ring 110 along line T, which extends through the
longitudinal axis A. For example, the central zone B can have a
planar area that is about 23% of the total planar area of the base
portion 18 as measured across the standing ring 110 along line
T.
[0047] Surrounding the central zone B is an outer zone B' of the
base portion 18. The outer zone B' includes a convex portion 124
extending from the inwardly extending portion 122. The convex
portion 124 is convex with respect to an outer surface of the base
portion 18. The convex portion 124 provides a secondary standing
ring/surface, as further described herein. In some instances, the
convex portion 124 is thus also referred to herein as secondary
standing ring/surface 124.
[0048] A generally planar portion 126 extends from the convex
portion 124. From the convex portion 124 the generally planar
portion 126 extends to a concave portion 128, which is concave with
respect to an outer surface of the base portion 18. A convex
portion 130, which is convex with respect to an outer surface of
the base portion 18, is spaced apart from the concave portion 128,
and is connected thereto with a generally planar portion 132.
[0049] Extending from the convex portion 130 away from the
longitudinal axis A is another planar portion 134. The planar
portion 134 extends away from the longitudinal axis A to a concave
portion 136, which is generally concave with respect to an outer
surface of the base portion 18. Extending from the concave portion
136 is a convex portion 138, which is generally convex with respect
to an outer surface of the base portion 18, and includes the
primary standing ring 110.
[0050] With particular reference to FIG. 5, the primary standing
ring 110 is configured to support the container 10 upright on a
first standing surface 150 when the base portion 18 is in the
as-blown configuration C of FIG. 5, which is before the container
10 is filled, such as by hot-filling. When the container 10 is
hot-filled, product heated to 195-205.degree. F. (90.5-96.degree.
C.) is loaded into the container 10, and then the finish 16 is
quickly capped with a suitable closure, such as the closure 180 of
FIGS. 7 and 8. Although the closure 180 is illustrated as a metal
lug closure (and the finish 16 of FIGS. 7 and 8 is modified to have
internal threads 42), the closure 180 can be any suitable closure,
such as a threaded plastic closure or a combi closure.
[0051] In response to receipt of the heated product and an
increased pressure resulting from closing the container 10 with the
closure 180, the base portion 18 moves outward along the
longitudinal axis A to the extended position D of FIG. 5. The
central zone B does not flex as it moves along the longitudinal
axis A to the extended position D. In contrast, portions of the
base portion 18 in the outer zone B' do flex. For example, the
secondary standing ring 124 flexes outward beyond the primary
standing ring 110 and the first standing surface 150. The secondary
standing ring 124 is configured to support the container 10 upright
on a second standing surface 152 when the base portion 18 moves to
the extended position D. When transitioning from the as-blown
position C to the extended position D and the retracted position
E1-E2 (described herein), any tilting experienced by the container
10, such as at the base portion 18, will typically be less than
about 2.degree. (such as less than about 0.5.degree.) as measured
between longitudinal axis A and axis A' of FIG. 5.
[0052] As the base portion 18 moves from the as-blown position C to
the extended position D, the side surface 118 of the central zone B
does not flex, but merely moves in a direction generally parallel
to the longitudinal axis A. Therefore, angle A.sub.1 of the side
surface 118 relative to the longitudinal axis A remains constant as
the base portion 18 moves from the as-blown position C to the
extended position D. In contrast, angle A.sub.2 of planar portion
126 relative to the longitudinal axis A, and angle A.sub.3 of
planar surface 134 relative to the longitudinal axis A, both
decrease as the base portion 18 moves from the as-blown position C
to the extended position D. Central zone B includes the ribbed
portions 120, which act as strengthening ribs to enhance the
rigidity of the central zone B.
[0053] As the base portion 18 moves from the as-blown position C to
the extended position D, various bend radii of the outer zone B'
change in response to flexing of the outer zone B' generally
outward. As illustrated in FIG. 5, bend radii R.sub.1-R.sub.5
change as follows: R.sub.1 increases (R.sub.1 is generally at the
primary standing ring 110); R.sub.2 decreases (R.sub.2 is generally
at the concave portion 136); R.sub.3 increases (R.sub.3 is
generally at the convex portion 130); R.sub.4 increases (R.sub.4 is
generally at the concave portion 128); and R.sub.5 decreases to
provide the secondary standing ring (R.sub.5 is generally at the
convex portion 124). As the central zone B moves from the as-blown
position C to the extended position D, distance D.sub.1 measured
from the gate area 114 to the first standing surface 150
decreases.
[0054] Movement of the base portion 18 from the as-blown position C
to the extended position D in response to increased pressure can be
summarized as follows:
TABLE-US-00001 R.sub.1 Increase R.sub.2 Decrease R.sub.3 Increase
R.sub.4 Increase R.sub.5 Decrease A.sub.1 Constant/Generally
Constant A.sub.2 Decrease A.sub.3 Decrease D.sub.1 Decrease
[0055] Exemplary dimensions of the base portion 18 in the as-blown
position C as compared to the extended position D are set forth
below:
TABLE-US-00002 Exemplary Exemplary As-Blown Extended Feature
Position C Position D Change R.sub.3 0.097 mm 0.11 mm +0.013 mm
R.sub.5 0.156 mm 0.139 mm -0.017 mm A.sub.1 37.degree. 37.degree.
0.degree. A.sub.2 74.degree. 57.degree. -17.degree. A.sub.3
101.degree. 63.degree. -38.degree. D.sub.1 0.6 mm 0.25 mm -0.35
mm
[0056] As the hot-filled product cools, temperature of the base
portion 18 decreases, and an internal vacuum is created within the
container. As a result, the base portion 18 moves from the extended
position D to retracted position E1-E2, which includes position E1,
E2, or any position between E1 and E2 illustrated in FIG. 6. For
reference purposes, FIG. 6 also illustrates the as-blown position
C. The base portion 18 may move, for example, to position E1, which
is beneath position C, to position E2, which is above and beyond
position C, or to any point therebetween.
[0057] As the base portion 18 moves from the extended position D to
the retracted position E1-E2, the central zone B moves along the
longitudinal axis A in the direction of the finish 16, but does not
substantially flex. Central zone B includes the ribbed portions
120, which act as strengthening ribs to enhance the rigidity of the
central zone B.
[0058] Most of the flexing of the base portion 18 occurs at the
outer zone B'. Therefore, angle A.sub.1 remains constant, or
generally constant, as the base portion 18 moves to the retracted
position E1-E2. Angles A.sub.2 and A.sub.3 increase, however, as
the base portion 18 moves to the retracted position E1-E2. As
explained above, in the retracted position E1-E2 the base portion
18 can be at E1, E2, or at any point therebetween. Thus for ease of
reference in FIG. 6, angles A1, A2, and A3 are each measured
relative to illustrated position C, which is generally between E1
and E2.
[0059] With respect to the bend radii R.sub.1-R.sub.5, they change
as follows, which is generally opposite to the change that occurs
during movement of the base portion 18 from the as-blown position C
to the extended position D described above: R.sub.1 decreases;
R.sub.2 increases; R.sub.3 decreases; R.sub.4 decreases; and
R.sub.5 increases. The distance that the gate area 114 is from the
first standing surface 150 increases from D.sub.1 in the as-blown
position C to D.sub.2 in the retracted position E1-E2. In the
retracted position E1-E2, the base portion 18 extends an additional
four millimeters, for example, into the container 10 as compared to
the as-blown position C.
[0060] The primary standing ring 110 also moves slightly inward in
the direction of the finish 16 to provide a third and final
standing surface 154 for the container 10. In general and as
illustrated in FIG. 6, in the retracted position E1-E2 the base
portion 18 is recessed within the container 10 so that D.sub.3,
measured between the standing surface 154 and about R.sub.5 is
greater than 0, and thus R.sub.5 is above 154. Movement of the base
portion 18 from the extended position D to the retracted position
E1-E2 due to vacuum response forces can be summarized as
follows:
TABLE-US-00003 R.sub.1 Decrease R.sub.2 Increase R.sub.3 Decrease
R.sub.4 Decrease R.sub.5 Increase A.sub.1 Constant/Generally
Constant A.sub.2 Increase A.sub.3 Increase D.sub.1 Increase
[0061] Exemplary dimensions of the base portion 18 in the as-blown
position C as compared to the retracted position E1-E2 are set
forth below:
TABLE-US-00004 Exemplary Exemplary as-Blown Retracted Feature
Position C Position E1-E2 Change R.sub.3 0.097 mm 0.069 mm -0.028
R.sub.5 0.156 mm 0.192 mm +0.036 A.sub.1 37.degree. 37.degree.
0.degree. A.sub.2 74.degree. 76.degree. +2.degree. A.sub.3
101.degree. 106.degree. +5.degree. D.sub.1 0.6 mm 0.6 mm 0
[0062] Exemplary differences between the pressure response of
extended position D and the vacuum response of the retracted
position E1-E2 are set forth below:
TABLE-US-00005 Exemplary Exemplary Pressure Vacuum Feature Response
Response Change Result R.sub.3 0.11 mm 0.069 mm -0.041 Decrease
R.sub.5 0.139 mm 0.192 mm +0.053 Increase A.sub.1 37.degree.
37.degree. 0.degree. Equal A.sub.2 57.degree. 76.degree. 19.degree.
Increase A.sub.3 63.degree. 106.degree. 43.degree. Increase D.sub.1
0.25 mm 0.6 mm 0.35 mm Increase
[0063] Movement of the base portion 18 from the as-blown position C
to the extended position D, and to the retracted position E1-E2
allows the container 10 to respond to the increased temperatures
and pressures associated with, for example, hot fill applications,
without having to include vacuum absorption features in the
sidewall 22. As a result, the sidewall 22 can have a generally
smooth and "glass-like" appearance, as illustrated in FIG. 1, for
example. Further, no base over-stroke operation is required with
the container 10. When transitioning from the as-blown position to
the extended position and retracted position, any tilting
experienced by the container 10 is less than about 2 degrees, such
as less than about 0.5 degrees measured between the longitudinal
axis A and A'.
[0064] At room temperature, there are between five and 15 inches Hg
of residual vacuum in the filled and cooled container. This
remaining vacuum is useful when the closure 180 is a metal lug
style closure, as illustrated in FIGS. 7 and 8. For example, the
closure 180 can include a freshness indicator/tamper evident button
182 at a center thereof (FIG. 8). The button 182 is drawn inward
when the container is unopened in response to vacuum pressures
therein. When the container 10 is opened, the button 182 pops out,
typically with an audible sound, which indicates to a consumer that
the product inside the container 10 is fresh. Geometry of the base
portion 18 can be optimized to work together with the closure 180
and the button 182 thereof in order to ensure that a proper amount
of residual vacuum is present within the container 10 for the
button 182 to operate properly.
[0065] With reference to FIGS. 7 and 8, the container 10 is
illustrated with a second container 10' stacked thereon. The
container 10' is similar to the container 10, and thus features of
the container 10' that are in common with the container 10 are
illustrated with the same reference numerals, but include the prime
(') symbol. In the retracted position E1-E2, the base portion 18'
of the container 10' provides a stacking surface. Specifically, the
generally planar portion 126' of the container 10' provides a
standing surface for container 10' atop the closure 180 of the
container 10. The closure 180 of container 10 can be received
within the base portion 18' such that generally planar portion 132'
of the container 10', which is generally vertical in the retracted
position E1-E2 of FIG. 8, surrounds the closure 180 in order to
securely receive the closure 180 within the base portion 18' and
prevent the container 10' from sliding off of the closure 180.
[0066] FIG. 9 is a graph of performance of an exemplary container
10 including base portion 18 according to the present teachings
showing displacement of the sidewall 22 at various vacuum
pressures. FIG. 9 is a similar graph of a prior art container. As
illustrated in FIG. 9, the prior art container experiences failure
or an undesirable response at a sidewall thereof at about only
11.32 PSI and after about 72 ml of displacement. In contrast, the
container 10 of the present teachings experiences reduced sidewall
performance at about 11.55 PSI and after about 125 ml of
displacement.
[0067] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *